Common focus energy emitters are known in the art.
U.S. Pat. No. 4,089,047 to Luderitz illustrates and describes three dimensional concave compound reflectors for focusing light from two or more light sources into an exit light beam.
U.S. Pat. No. 4,754,381 to Downs illustrates and describes three dimensional ellipsoidal concave reflector systems for the concentration of light, ultrasonic or shock waves, and the like, into an exit beam.
The aforesaid reflectors have a partial elliptical shape in an imaginary plane including an exit beam axis defined between a common focus energy source and an exit beam aperture. The aforesaid reflectors bound an imaginary body of revolution formed by revolution of the partial elliptical shape about the energy emitter axis. However, since nearly all the rays emitted by the energy sources are not on the imaginary plane, so correspondingly the aforesaid reflectors focus only a very small proportion of the total available energy emitted by the energy sources in the direction of their exit beam axes.